Jack Good: Cryptographer whose work with Alan Turing at Bletchley Park was crucial to the War effort

In the 1960s Jack Good, known in the United States as an academic working in statistics and mathematics, used to drive around the campus of Virginia Tech University in a car which sported the personalised number plate 007 IJG. It was his oblique way of referring to what for decades he could not speak about – his important wartime role as a codebreaker at Bletchley Park, where he and colleagues did work which is credited with shortening the war.

He worked closely with Alan Turing, Bletchley's presiding genius, and other near-legendary figures such as Max Newman and Donald Michie. They used a mixture of rudimentary computers and sheer brainpower to break German codes and give Allied commanders huge tactical advantages.

Good was 24 when he arrived at Bletchley, initially ruffling feathers by sleeping during a night shift but quickly redeeming himself by pointing out a procedure for one machine which had not occurred to his more experienced colleagues. As he later explained it, in the all-but-impenetrable language of the statistical cryptanalyst, "I had an extremely simple idea that cut the work by about 50 per cent. It was the replacement of scores such as 3.6 decibans (stored as 36 centibans) by 7 half-decibans. Nearly all the entries, of which there were a few thousand, could then be expressed by a single digit." [A ban is a logarithmic unit that measures information]. This was one of Good's most important insights, but it was just one of thousands of ideas, notions, thoughts and speculations he came up with in his long career. A prolific author with many books and almost a thousand papers to his credit, his published writings ran to about two million words in which he ranged over statistics, physics, mathematics and philosophy. One reviewer summed up his record: "For more than 30 years I.J. Good has been prodding, stimulating, criticizing, enlightening, surprising and amusing colleagues with his dazzling insights into the dark mysteries of probability and scientific inference."

His first insight, and one of his most remarkable, came when he was nine years old. Confined to bed with diphtheria, he mulled over the square root of 2 and came up with a new understanding of its mathematical subtleties. Seventy years later Good said: "I'm proud of that, even now, because if there was any single instance in my life that shows that I had a little bit of mathematical genius, I think that was it. At the age of nine, it wasn't bad to make a discovery that was described as one of the greatest achievements of the ancient Greek mathematicians."

Good, whose original name was Isidore Jacob Gudak, was the son of a Russian mother and Polish father who met in London. His father was first a watchmaker and later a prominent antique-jewellery dealer near the British Museum. At Haberdashers' Aske's School in Hampstead Good was not an all-rounder: "History I did not enjoy," he recalled. "I would always fall asleep during history lessons."

But he was recognised as a maths prodigy and went on to win a scholarship to Jesus College, Cambridge, where he took a first-class degree and a PhD in mathematics. His aptitude for maths – and for chess – drew him to the attention of Hugh Alexander, a chess champion who was also a senior figure at Bletchley. Recruited by Alexander in 1941, Good spent the rest of the war there, immersed in profound statistical thought and in designing and operating primitive computers. He was one of the few who could keep up with Turing's sometimes eccentric brilliance.

Their efforts paid huge dividends and almost certainly shortened the war. He once mused: "There must have been occasions when we read a message from Hitler to his generals before the general read it." Good once summed up: "The feeling that we were helping substantially, and perhaps critically, to save much of the world – including Germany – from heinous tyranny was a hard act to follow."

Good and the others always acknowledged the primacy of Turing as a thinker and problem solver. "I won't say that what Turing did made us win the war," he once observed. "But I daresay we might have lost it without him."

In addition to working long hours on breaking Nazi codes, Turing, Good and others found time to indulge in futurology. They conjectured that computers might become smaller – they were then the size of a room – and that they might play chess. They pondered on artificial intelligence.

After the war he joined Turing and Newman at Manchester University, where they achieved an important advance by creating the first computer controlled by an internally stored programme. But after a few years he returned to the secret world, spending a decade at Government Communications Headquarters (GCHQ), Bletchley's peacetime successor. A variety of posts followed before he spent three years teaching at Oxford.

"I found Oxford a bit stiff, actually," he recalled. "It was somewhat taboo to talk shop at dinner time. One could talk about cricket, and things like that. I wasn't sorry to leave to come to America."

His 1967 move across the Atlantic took him to Virginia Tech, which he found much more congenial and where he spent decades. He insisted however: "I always thought of myself as British."

He attracted various honours and awards, and doubtless would have accumulated more had his work at Bletchley and GCHQ not remained top secret. He was once described as "the overlooked father of computation."

He was consulted by Stanley Kubrick when the producer was researching his classic film 2001: A Space Odyssey (1968). In the movie a spaceship's on-board computer develops a mind of its own, with lethal consequences: Good largely viewed computers as a marvellous tool, but occasionally suspected that they might ultimately become dangerous.

For years Good stuck to his thesis that computers might have personality traits, arguing: "My computer tells lies and often forces me to shut down improperly. Such behaviour in a human would be called neurotic."

He remained to the end as fascinated with numbers as he had been at the age of nine. He said of reaching Virginia: "I arrived in the seventh hour of the seventh day of the seventh month of year seven of the seventh decade, and I was put in apartment 7 of block 7, all by chance. I seem to have had more than my fair share of coincidences. I have an idea that God provides more coincidences the more one doubts Her existence, thereby providing one with evidence without forcing one to believe. When I believe that theory, the coincidences will presumably stop."

David McKittrick

Isidore Jacob Gudak (Irving John Good), mathematician and cryptographer: born London 9 December 1916; died Radford, Virginia 5 April 2009.

Arts and Entertainment
Gregg Wallace in Summer's Supermarket Secrets
tv All of this year's 15 contestants have now been named
Arts and Entertainment
Inside the gallery at Frederick Bremer School in Walthamstow
tvSimon Usborne goes behind-the-scenes to watch the latest series
Life and Style
A picture taken on January 12, 2011 shows sex shops at the Paris district of Pigalle.
newsThe industry's trade body issued the moratorium on Friday
Winchester College Football (universally known as Winkies) is designed to make athletic skill all but irrelevant
Life...arcane public school games explained
Have you tried new the Independent Digital Edition apps?
ebooksAn evocation of the conflict through the eyes of those who lived through it
Arts and Entertainment
Could we see Iain back in the Bake Off tent next week?
tv Contestant teased Newsnight viewers on potential reappearance
Life and Style
Silvia says of her famous creation: 'I never stopped wearing it. Because I like to wear things when they are off the radar'
fashionThe fashion house celebrated fifteen years of the punchy pouch with a weighty tome
i100(and it's got nothing to do with the Great British Bake Off)
Angelina Jolie with her father Jon Voight
peopleAsked whether he was upset not to be invited, he responded by saying he was busy with the Emmy Awards
Bill Kerr has died aged 92
peopleBill Kerr appeared in Hancock’s Half Hour and later worked alongside Spike Milligan and Peter Sellers
news It's not just the world that's a mess at the moment...
footballPremiership preview: All the talking points ahead of this weekend's matches
Keira Knightley poses topless for a special September The Photographer's issue of Interview Magazine, out now
The Ukip leader has consistently refused to be drawn on where he would mount an attempt to secure a parliamentary seat
voicesNigel Farage: Those who predicted we would lose momentum heading into the 2015 election are going to have to think again
Arts and Entertainment
Cara Delevingne made her acting debut in Anna Karenina in 2012
film Cara Delevingne 'in talks' to star in Zoolander sequel
Mario Balotelli pictured in his Liverpool shirt for the first time
Life and Style
Travel Shop
the manor
Up to 70% off luxury travel
on city breaks Find out more
Up to 70% off luxury travel
on chic beach resorts Find out more
sardina foodie
Up to 70% off luxury travel
on country retreats Find out more
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

C# Algo-Developer (BDD/TDD, ASP.NET, JavaScript, RX)

£45000 - £69999 per annum + Benefits + Bonus: Harrington Starr: C# Algo-Develo...

Senior Data Scientist (Data Mining, Apache Mahout, Python,R,AI)

£60000 - £70000 per annum + Benefits + Bonus: Harrington Starr: Senior Data Sc...

Data Scientist (SQL,Data mining, data modelling, PHD, AI)

£50000 - £80000 per annum + benefits+bonus+package: Harrington Starr: Data Sci...

Java Developer - 1 year contract

£350 - £400 Per Day: Clearwater People Solutions Ltd: Our client based in Cent...

Day In a Page

Ukraine crisis: The phoney war is over as Russian troops and armour pour across the border

The phoney war is over

Russian troops and armour pour into Ukraine
Potatoes could be off the menu as crop pests threaten UK

Potatoes could be off the menu as crop pests threaten UK

The world’s entire food system is under attack - and Britain is most at risk, according to a new study
Gangnam smile: why the Chinese are flocking to South Korea to buy a new face

Gangnam smile: why the Chinese are flocking to South Korea to buy a new face

Seoul's plastic surgery industry is booming thanks to the popularity of the K-Pop look
From Mozart to Orson Welles: Creative geniuses who peaked too soon

Creative geniuses who peaked too soon

After the death of Sandy Wilson, 90, who wrote his only hit musical in his twenties, John Walsh wonders what it's like to peak too soon and go on to live a life more ordinary
Caught in the crossfire of a cyber Cold War

Caught in the crossfire of a cyber Cold War

Fears are mounting that Vladimir Putin has instructed hackers to target banks like JP Morgan
Salomé's feminine wiles have inspired writers, painters and musicians for 2,000 years

Salomé: A head for seduction

Salomé's feminine wiles have inspired writers, painters and musicians for 2,000 years. Now audiences can meet the Biblical femme fatale in two new stage and screen projects
From Bram Stoker to Stanley Kubrick, the British Library's latest exhibition celebrates all things Gothic

British Library celebrates all things Gothic

Forthcoming exhibition Terror and Wonder: The Gothic Imagination will be the UK's largest ever celebration of Gothic literature
The Hard Rock Café's owners are embroiled in a bitter legal dispute - but is the restaurant chain worth fighting for?

Is the Hard Rock Café worth fighting for?

The restaurant chain's owners are currently embroiled in a bitter legal dispute
Caribbean cuisine is becoming increasingly popular in the UK ... and there's more to it than jerk chicken at carnival

In search of Caribbean soul food

Caribbean cuisine is becoming increasingly popular in the UK ... and there's more to it than jerk chicken at carnival
11 best face powders

11 best face powders

Sweep away shiny skin with our pick of the best pressed and loose powder bases
England vs Norway: Roy Hodgson's hands tied by exploding top flight

Roy Hodgson's hands tied by exploding top flight

Lack of Englishmen at leading Premier League clubs leaves manager hamstrung
Angel Di Maria and Cristiano Ronaldo: A tale of two Manchester United No 7s

Di Maria and Ronaldo: A tale of two Manchester United No 7s

They both inherited the iconic shirt at Old Trafford, but the £59.7m new boy is joining a club in a very different state
Israel-Gaza conflict: No victory for Israel despite weeks of death and devastation

Robert Fisk: No victory for Israel despite weeks of devastation

Palestinians have won: they are still in Gaza, and Hamas is still there
Mary Beard writes character reference for Twitter troll who called her a 'slut'

Unlikely friends: Mary Beard and the troll who called her a ‘filthy old slut’

The Cambridge University classicist even wrote the student a character reference
America’s new apartheid: Prosperous white districts are choosing to break away from black cities and go it alone

America’s new apartheid

Prosperous white districts are choosing to break away from black cities and go it alone